Southern California -- this just in

Dirty adult diapers dumped in upscale Newport Beach neighborhood

A serial dirty diaper dumper has struck again in Orange County, leaving about a dozen used diapers on streets in upscale Corona del Mar.

A Newport Beach police still don't know who is responsible for "disposing of the diapers in this manner," according to spokeswoman Kathy Lowe.

The diapers last appeared in May, prompting city code enforcement officers to try to find the person responsible. But unless the person is caught in the act, it may be difficult to cite them for littering, city officials said.

The used diapers seem to be adult-sized and first began appearing along a stretch of East Coast Highway between Cameo Highlands Drive and Morning Canyon Road in the summer of 2011. One nearby resident said she'd seen the diapers every few months, but by early winter, they would appear every few weeks.

In December 2011, there were at least three separate occasions where the diapers littered the roadway, causing cyclists to swerve to avoid them before city crews were able to remove them.

Newport Beach's municipal code prohibits throwing garbage on streets and in public places, and fines start at $100. Anyone who sees someone dumping diapers should call general services at (949) 644-3055.